Method of fabricating CMOS devices having a single work function gate electrode by band gap engineering and article made thereby

Abstract

A method utilizing a common gate electrode material with a single work function for both the pMOS and nMOS transistors where the magnitude of the transistor threshold voltages is modified by semiconductor band engineering and article made thereby.

Description

RELATED APPLICATIONS [0001] This application relates to the application entitled “CMOS devices with a Single Work Function Gate Electrode and Method of Fabrication,” filed on Sep. 28, 2005.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to the field of semiconductor integrated circuit manufacturing, and more particularly to CMOS (complementary metal oxide semiconductor) devices having gate electrodes with a single work function. [0004] 2. Discussion of Related Art [0005] During the past two decades, the physical dimensions of MOSFETs have been aggressively scaled for low-power, high-performance CMOS applications. In order to continue scaling future generations of CMOS, the use of metal gate electrode technology is important. For example, further gate insulator scaling will require the use of dielectric materials with a higher dielectric constant than silicon dioxide. Devices utilizing such gate insulator materials demonstrate vastly ...

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Problems solved by technology

For such devices, a “mid-gap” work function gate electrode that is located in the middle of the p and n channel work function range is inadequate.

A mid-gap gate electrode typically results in a transistor having either a threshold voltage that is too high for high-performance applications, or compromised SCEs when the effective channel doping is reduced to lower the threshold voltage.

Therefore, a single mid-gap gate material is also incapable of achieving low threshold voltages for both pMOS (a MOSFET with a p-channel) and nMOS (a MOSFET with an n-channe...

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